In a small bowl, whisk together the mayonnaise, lime juice, cumin, garlic powder, salt and cayenne.
Place the shredded coleslaw mix, green onions, and cilantro into a large bowl. Pour the dressing over evenly and toss to coat.
If you have time, refrigerate the cilantro lime slaw for an hour to let the flavors develop. Stir again before serving. Serve chilled.